Lactone stabilizing compositions

ABSTRACT

This invention provides a novel class of compounds and compositions and synthetic methods related to lactone antioxidant 3-arylbenzofuranones. The compounds may be useful to prevent yellowing and deterioration of organic materials preferably polymers, such as polyurethane foams as one example. The lactone antioxidants may be polymeric, and may also be liquid or paste in physical form at room temperature. Although it is not necessary for its stabilizing properties, the compositions may, in some species, bear one or more reactive primary OH groups on the polymer chains. The chains may also contain oligomeric oxyalkylene ether and aliphatic ester functional groups, in one embodiment of the invention.

FIELD OF THE INVENTION

The present invention relates to compositions comprising an organicmaterial, such as a polymer, and an oligomeric lactone for use as astabilizers. The inventive compositions may be employed forstabilization of organic materials against oxidative, thermal, orlight-induced degradation. The invention is directed to novel oligomericlactones.

BACKGROUND OF THE INVENTION

Various compositions are known that function to stabilize organicmaterials against oxidative, thermal or light-induced degradation. Suchstabilization compositions may have broad applications in thermoplasticssuch as polyolefin, thermoset resins such as polyurethanes, and coatingformulations. One problem with polyurethane foams, for example, is thatsuch foams tend to yellow after a certain period of time. Yellowing offoam products is undesirable. Such yellowing may be caused by NOx gasfading or UV radiation.

U.S. Pat. Nos. 4,325,863 and 4,338,244 to Hinsken disclose 3-arylbenzofuran-2-ones and their dimers as new class of stabilizers invarious organic polymers such as polyolefins, polyurethanes andpolyesters.

U.S. Pat. Nos. 5,367,008 and 5,369,159 and 5,428,162 to Nesvadbadisclose the preparation of various 3-(alkoxyphenyl) benzofuran-2-onesand 3-(acyloxyphenyl) benzofuran-2-one derivatives, for use as polymerstabilizers.

The prior art provides a number of relatively non-reactive, solidstabilizers. Solids are difficult to use in manufacturing processes.Solids provide difficulties in handling, migration, fogging, andblooming.

New and more effective stabilizing compounds are needed in the industry.This invention provides such compounds.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made to the embodiments of the invention, one ormore examples of which are set forth below. Each example is provided byway of explanation of the invention, not as a limitation of theinvention. In fact, it will be apparent to those skilled in the art thatvarious modifications and variations can be made in this inventionwithout departing from the scope or spirit of the invention.

This invention provides a novel class of compounds and compositions andsynthetic methods. In one aspect of the invention, the compositions maycomprise polymeric or oligomeric lactone antioxidants, such aspoly(oxyalkylene) chain(s) substituted 3-arylbenzofuranones orpoly(caprolactone) chain(s) substituted 3-arylbenzofuranones. Theinventive lactone antioxidants may be polymeric or oligomeric, which maybe liquid or pastes in nature at room temperature. In many applications,liquid or paste forms of such compounds provide a remarkable andsurprising advantage. Although it may not be necessary for itsstabilizing properties, the compositions may bear one or more reactiveprimary —OH groups on the polymer chains. For some applications, theterminal group(s) of the polymer chain(s) is not believed to be criticalwith regard to the functioning of the polymeric lactones in stabilizercompositions. The chain(s) may also contain oxyalkylene ether andaliphatic ester functional groups or radicals.

The inventive liquid lacones polymeric/oligomeric chains may containoxyalkylene segments (such as ethylene oxide and/or propylene oxide,etc, and the EO/PO ratio can be designed as such to achieve desiredhydrophilic and/or hydrophobic properties) and/or aliphatic estersegments (hydrophobic). This affords the opportunity to “tune” thelactone antioxidants for desirable compatibility in various media suchas thermosets (polyurethane), thermoplastics (PET, PP, PS, PC and thelike), wax, aqueous systems (liquid hand soap, detergents, sunscreens,fabric softeners etc. consumer products), and coatings.

Lactones bearing unique polymeric/oligomeric chains may also becomprised of specific combination of EO/PO/aliphatic esters that arecompatible with most of the above-mentioned applications. The liquidnature of the inventive polymeric lactones provides ease of handlingduring the application process. That is, the compositions may desirablybe liquids or pastes at room temperature, making it much easier to applythe compositions in manufacturing processes. And thepolymeric/oligomeric nature of the inventive lactones provides highermolecular weight and better compatibility with application media, thusis less volatile, and less prone to migrate, bloom and plate-out.

In some applications, primary hydroxy groups are present on theinventive lactone molecules. These structures offer superior reactivityin polyurethane, PET and coating systems. Thus the polymeric lactonemolecules may be chemically attached on to the application media if suchis desirable. The inventive polymeric UV absorbers may solve or mitigatemigration, leaching, fogging, plate-out, and extraction problems, eachof which is highly undesirable.

The inventive polymeric lactone antioxidants 3-arylbenzofuranones, whenused along with other additives such as UV absorbers, otherantioxidants, and light stabilizers, may significantly reduce the gasfading (NOx) and UV radiation induced yellowing of white polyurethanefoam. The compositions may be provided in liquid form, and are reactiveinto the foam, which is a significant advantage. That is, thesecompositions are truly polymeric or oligomeric, having in someapplications polyoxyalkylene and aliphatic polyester blockcopolymer/oligomer chains.

The inventive lactone stabilizers may be liquid and polymeric. They mayprovide ease of handling, processing and metering. The inventive lactonestabilizers may bear primary —OH groups at the end of polymer chains.They may be completely reactive in polyurethane, coatings, PET, andpolycarbonate applications if such is desirable. They may provideantioxidant functions to resist undesirable extraction, migration,fogging, and leaching out of the polymer matrix.

In one application, the compounds of the invention may be described asfollows:

wherein:

R₁-R₈ are each independently selected from the group consisting of:

-   -   H, F, Cl, Br, I, C₁-C₂₀ alkyls, C₁-C₂₀ cycloalkyls, C₁-C₂₀        alkoxy groups, C₇-C₂₀ phenylalkyls, and phenyl groups;

A comprises a C₂-C₂₀ alkyl group or a divalent oligomeric oxyalkyleneradical;

Z comprises a C₂-C₂₀ alkyl or a divalent oligomeric ester radical; and

G is an end group and is selected from the group consisting of:

-   -   H, C₁-C₁₀ alkyls, alkyl carbonyls and aryl carbonyls.

The composition “A” recited above may comprise a divalent oligomericoxyalkylene radical, which may provide the structure:

wherein:

EO comprises ethylene oxide or a derivative thereof;

PO comprises propylene oxide or a derivative thereof;

R_(g) comprises a divalent C₁-C₂₀ alkyl radical;

x, y and w are independently selected from the group consisting of: zeroand positive integers or fractions between 1 and 20; wherein

x+y+w is equal or greater than 1; and wherein

R₁₀ comprises H or a C₁-C₂₀ alkyl group.

Furthermore, the Z group may be comprised of a divalent oligomeric esterradical, having the structure:

wherein:

R₁₁ and R₁₂ are independently selected from H or C₁-C₁₀ alkyl groups;

n comprises an integer between 1 and 10; and

m comprises any positive integer or fraction between 1 and 20.

In another embodiment, a compound of the invention may also berepresented by the formula:

wherein R1, R3, R5-R8, A, Z and G are as defined above.

Still in another embodiment, a compound of the invention may also berepresented by the formula:

wherein:

R₁, and R₃ are as defined above, and

q is a positive integer between 1 and 20, and

t is a positive integer between 0 and 20, and wherein q+t is equal to orgreater than 3.

Further specifically, a compound of the invention may be represented bythe formula:

wherein q and t are as defined above.

The compounds according to the invention may be effective antioxidantswhen used alone or in combination with other conventional antioxidants,for stabilizing organic materials, for example for coatings and a largenumber of polymers. For all applications in which a liquid, oligomericand non-migration properties are highly desirable, the inventivecompounds afford advantages over conventional lactone antioxidants.These polymers may be polyurethane, polyolefin, polycarbonate,polyamide, epoxyl resin, polyethers such as polyethylene glycol,polypropylene glycol or polytetramethylene glycol, and the like.

The stabilizing compositions are incorporated into the organic materialby the conventional methods, for example in any desired phase during themanufacture of shaped products. They can, for example, be mixed in theform of a liquid, a paste, a powder with other materials, suspensions oremulsions or solutions into the polymer, which can be in the form of apowder, melt, solution, suspension or emulsion.

In stabilizing polyurethane foam in particular, the inventive compoundscan be used with the following classes of additives:

Class A: Benzotriazoles are (in general) those compounds that conform tothe structure represented as the following:

wherein R₁₃, R₁₄, and R₁₅ are independently selected from hydrogen, agroup having a formula C_(a)H_(b)N_(c)O_(d)S_(e) wherein a, b, c, d, ande are from 0 to 30, and halogen.

Class B: Hindered phenols or BHT derivatives, and related compoundstypically conform to the structure of the following:

wherein R₁₆ is selected from the group consisting of hydrogen, a grouphaving a formula C_(a)H_(b)N_(c)O_(d)S_(e) wherein a, b, c, d, and e maybe from 0 to 30, and halogen.

Class C: Secondary diphenylamines may conform to the structure of thefollowing

wherein R₁₇ and R₁₈ are individually selected from the group consistingof hydrogen, a group having a formula C_(a)H_(b)N_(c)O_(d)S_(e) whereina, b, c, d, and e are from 0 to 30, and halogen.

Class D: other conventional Lactone-based antioxidants may include thosecompounds that conform to the structure of the following:

wherein R₁₉ to R₂₇ are individually selected from the group consistingof hydrogen, a group having a formula C_(a)H_(b)N_(c)O_(d)S_(e) whereina, b, c, d, and e are from 0 to 30, and halogen.

Several examples of the synthesis and application of the invention areshown below, in written form of Examples, and in data produced forTables.

SYNTHETIC EXAMPLES OF THE INVENTION Example 1

Two hundred seventy four grams of 2,4-di-tert-butylphenol, 165 g of4-hydroxymandelic acid and 530 ml of acetic acid were combined in a twoliter three neck round bottom flask equipped with a temperature probe,stirring apparatus and condenser. The mixture was heated to 95° C., atwhich, 2.6 g of methanesulfonic acid were added. The reaction wasallowed to proceed at 95° C. for three hours. After cooling to roomtemperature and sitting overnight, the precipitated product wascollected via filtration. This filtercake was washed several times withacetic acid until the precipitate was white. After drying in a 50° C.oven, 175 g of 5,7-di-tert-butyl-3-(4-hydroxyphenyl)benzofuran-2-oneproduct having a melting point of 189-191° C. were obtained.

Example 2

In a three liter three neck round bottom flask, a solution of 32.4 g ofsodium hydroxide in 810 ml of water was formed. With stirring, 91.6 g of5,7-di-tert-butyl-3-(4-hydroxyphenyl)benzofuran-2-one were added and themixture heated to 80° C. under a nitrogen atmosphere. Once at 80° C., 27ml of 2-chloroethanol were added and the reaction held at 80° C. for twohours. After cooling to room temperature, a solution of 99 ml ofconcentrated hydrochloric acid in 1251 ml of water was added and thereaction held again at 80° C. for an additional hour. Once cooled toroom temperature, the liquid was decanted and the remaining soliddissolved in 500 ml of methylene chloride. This solution was washed oncewith 300 ml of water. After drying the methylene chloride layer overmagnesium sulfate and stripping, 92.6 g of5,7-di-tert-butyl-3-[4-(2-hydroxy-ethoxy)-phenyl]benzofuran-2-one, alight yellow solid remained. This solid can be further recrystallizedfrom ethanol/water.

Example 3

Fifteen grams of5,7-di-tert-butyl-3-[4-(2-hydroxy-ethoxy)-phenyl]benzofuran-2-one, 13.5g of ε-caprolactone and 0.3 g of 50% hypophosphorous acid were chargedto a 100 ml three neck flask. Under a nitrogen atmosphere, the mixturewas heated to 100° C. and held for three hours. Twenty four grams ofviscous liquid product having a light yellow color were obtained.

Example 4

Three hundred grams of5,7-di-tert-butyl-3-(4-hydroxyphenyl)benzofuran-2-one, 500 g of tolueneand 3 g of lanthanum phosphate catalyst were charged into an autoclave.The reaction mixture was purged several times with nitrogen gas (to apressure of 60 PSIG) and finally pressurized to 5 PSIG of nitrogen.After heating the autoclave to 121° C., ethylene oxide was added to thereaction mixture until the pressure in the reactor reached 60 PSIG.After the pressure dropped to 30 PSIG due to consumption of ethyleneoxide, more ethylene oxide was added to the reactor in the same fashionas previously described until a total of 192 g of ethylene oxide hadbeen added. Afterwards, the reaction mixture was post-cooked for a totalof 30 minutes. Toluene was removed via vacuum stripping yielding 472 g(96%) of a light yellow viscous liquid.

Article Production and Performance Testing for Inventive LiquidPolymeric Lactone Antioxidants

a) Polyether Foam Article Formation

The inventive lactone antioxidants were incorporated with or withoutother additives to produce (in one particular embodiment of theinvention) polyurethane foam in accordance with the followingformulation and procedure: Component Amount F3022 Polyol (from Bayer)100 grams Water 4.53 ml DABCO 33LV (catalyst, from Air Products) 0.15 mlDABCO T10 (catalyst) 0.32 ml L520 Silicone (from Crompton) 1.0 mL 80/20Toluene diisocyanate (Bayer, 112 index) 49.0 ml Reactint ® Blue X3LV asnoted Inventive Polymeric Lactone Antioxidants as noted Additive fromClass A as noted Tinuvin ® 326 Additive from Class B as noted Irganox ®1135 Additive from Class C as noted Irganox ® 5057 Additive from Class Das noted Irganox ® HP 136

Upon mixture within a reaction vessel, the reaction created a “health”bubble (indicating gelation and blowing balance), and the vessel wasthen exposed to 160° C. (generated within a conventional oven tosimulate actual heat history encountered on an industrial productionlevel) for about 3 minutes allowing the material to cure to form a foambun. The resultant foam buns were then analyzed for performance, asdiscussed in details below.

b) Performance Characteristics of Polyether Foams Including Inventive

Polymeric Liquid Lactone Antioxidants The white foams made in accordancewith formulation and process as described in Section a), were all testedfor standard foam performance, in terms of rise time, tack time, and bunheight, and compared with the control polyether foams either made withconventional commercial lactone antioxidant Irganox® HP 136 or madewithout additive. Measurements within 5% of the control are consideredacceptable for the finished foam product. The measurements aresummarized in Table 1. TABLE 1 Foam Performance of Inventive orComparative Lactone Antioxidants Sample Additive Loading Rise Time TackTime Bun Height Foam # (Mw) (php) (minutes) (minutes) (mm) A1 N/A N/A1.50 3 226 A2 HP-136 1.0 1.54 3 230 (Mw 350.7) A3 Example 3 1.0 1.52 3234 (Mw 724) A4 Example 3 2.0 1.52 3 228 (Mw 724) A5 Example 4 1.0 1.503 232 (Mw 558) A6 Example 4 1.6 1.55 3 233 (Mw 558)

Additionally, the foams produced exhibited good resiliency and densitiesmeasured at about 1.5 pounds per cubit foot. Thus, the inventivepolymeric lactone antioxidants provide acceptable polyurethane foamarticles as compared with control samples.

c) Extraction Measurements From Polyurethane Foams

The polyurethane foams produced in above Section b) were analyzed forextraction levels using the following method. The extraction testinvolved cutting 1 gram of the cured foam from the center of the sampleand post-curing the cut foam for another 20 minutes at 160° C. in aglass jar. After cooling to room temperature, 75 grams of methanol werethen added to the glass jar that was then capped for 1 hour. The foamwas then removed and the extract solution was analyzed to detect thepercentages of the lactone antioxidants being extracted out. The resultsare summarized in Table 2. TABLE 2 Foam Extraction Tests of Inventive orComparative Lactone Antioxidants Sample Additive Loading Extraction Foam# (Mw) (php) (%) A1 N/A N/A Not detectable A2 HP-136 1.0 >96 (Mw 350.7)A3 Example 3 1.0 <5 (Mw 724) A4 Example 3 2.1 <5 (Mw 724) A5 Example 41.0 <5 (Mw 558) A6 Example 4 1.6 <5 (Mw 558)

Based on the molecular weight of these additives, 1.0 php of HP-136 ismolar equivalent to 2.1 php of inventive additive from Example 3, and1.6 php of inventive additive from Example 4. As suggested from Table 2,the inventive liquid polymeric lactone antioxidants provide significantimprovement in the foam extraction test, comparing to comparativeexamples such as commercial product HP-136.

d) Protection of Colorants from Thermal Discoloration in PolyurethaneFoam

Liquid polymeric colorant Reactint® Blue X3LV (available from MillikenChemical) is widely used for the coloration of polyurethane foam, and isknown to be prone to thermal discoloration during foam articleformulation. Thus, the blue foams were made in the presence of 1 phpBlue X3LV with or without inventive and comparative lactoneantioxidants, in accordance with formulation and process similar tothose as described Section a), with the exception that after thereaction created a “health” bubble (indicating gelation and blowingbalance), the vessel was then exposed to 185° C. (generated within amicrowave oven to simulate actual heat history encountered on a largeindustrial production environment) for about 10 min before it wasexposed to 160° C. (generated by a conventional oven) for 3 minutes tocure the foam bun. The foam buns were sliced in half, and then comparedreading at the center of the foam bun (usually where the discolorationoccurs) in CMC for delta E with the reading at the outer section of thefoam bun (usually where no discoloration occurs). The results aresummarized in Table 3. TABLE 3 Stabilize Reactint ® Blue X3LV fromThermal Discoloration during Polyurethane Foam Formation Sample LoadingObservation at the Foam # Additive Mw (php) Delta E center of foam bunA7 Control n/a n/a 4.6 some yellowing or (X3LV only) color loss A8HP-136 350 1 1.8 No color change A9 Example 3 724 1 1.9 No color changeA10 Example 4 558 1 2.4 Trace yellowing or color loss A11 Example 4 5581.5 1.4 No color change

The data in Table 3 suggested that the inventive polymeric liquidlactone antioxidants were very effective in stabilization of polymericcolorants such as Blue X3LV from thermal degradation during thepolyurethane foam production process.

e) Protection of Pure Polyol from Thermal Degradation/Yellowing duringPolyurethane Foam Formation

Polyols are known to be very prone to oxidation. In order to retain thephysical and chemical properties, almost all commercial polyols areprotected with conventional hindered phenol antioxidants for storage andtransportation. One major side effect of the hindered phenols is thatthey cause discoloration/yellowing during polyurethane article formationand when exposed to exhaust gas (NOx). An antioxidant which caneffectively protect the intergraty of polyols without causing polymerssuch as polyurethane foam yellowing and compatible with polyols ishighly desired. In order to test the effectiveness of the inventivepolymeric lactone antioxidants, the white foams (without adding anycolorant) were made using pure polyol (no conventional antioxidantpackage presence) with or without inventive and comparative lactoneantioxidants, in accordance with formulation and process similar tothose as described Section a), with the exception that after thereaction created a “health” bubble (indicating gelation and blowingbalance), the vessel was then exposed to 185° C. (generated within amicrowave oven to simulate actual heat history encountered on a largeindustrial production environment) for about 10 min before it wasexposed to 160° C. (generated by a conventional oven) for 3 minutes tocure the foam bun. The foam buns were sliced in half, and then comparedreading at the center of the foam bun (usually where the discolorationoccurs) in CMC for delta E with the reading at the outer section of thefoam bun (usually where no discoloration occurs). The results aresummarized in Table 4. TABLE 4 Performance of Compositions inStabilizing Pure Polyol from Thermal Degradation/Yellowing During PUFoam Formation Sample Loading Observation at the Foam # Additive Mw(php) Delta E foam center A12 Control n/a n/a 48.1 Very yellow (Purepolyol) A13 HP-136 350 0.1 1.1 No color change A14 HP-136 350 1 4.2 Nocolor change A15 Example 3 724 0.1 1.5 No color change A16 Example 3 7241 2.3 No color change A17 Example 4 558 0.1 2.6 No color change A18Example 4 558 1 2.8 No color change

Thus, the inventive polymeric liquid lactone antioxidants are veryeffective in stabilizing pure polyols from thermal degradation.

f) Protection of Polyurethane Foam Made with Pure Polyols from GasFading

In order to test the effectiveness of the inventive polymeric lactoneantioxidants in stabilizing the pure polyols from gas (NOx) fading andcomparing the performance with commonly used conventional hinderedphenol antioxidant package, the white foams (without adding anycolorant) were made using pure polyol (no conventional antioxidantpackage presence), as well as regular polyols (with the conventionalstabilizer package presences) with or without inventive and comparativelactone antioxidants, in accordance with formulation and process similarto those as described in Section a). After curing, the foam buns weresliced in half, and small pieces of foam samples (diameters of 10 cm×5cm×2 cm) were cut from the center of each foam bun. These foam sampleswere all tested under NOx gas chamber (NOx concentration is 1 ppm) fordiscoloration at different exposure time. Those foam samples exposed todifferent amounts of time in NOx chamber testing were then comparedreading in CMC for delta E with respected unexposed foam samples. Theresults are summarized in Table 5. TABLE 5 Performance of Compositionsin Stabilizing PU Foam Formation Made with Pure Polyol from Gas FadingSample Loading Delta Observation of Foam # Additive Mw (php) E exposedfoam sample A19 Control 1 n/a n/a 39.4 Yellow-brownish (regular polyol)A20 Control 2 n/a n/a 13.4 Slight yellow (Pure polyol) A21 HP-136 3500.1 21.5 Slight yellow A22 Example 3 724 0.1 16.7 Slight yellow A23Example 4 558 0.1 17.1 Slight yellow A24 Example 4 558 0.4 17.5 Slightyellow

It is thus clear that the inventive liquid polymeric lactoneantioxidants are superior to conventional hindered phenol antioxidantpackage in stabilizing polyol from NOx fading.

g) Reduction of Discoloration in White Polyurethane Foam

Several white foams made in accordance with formulation and process asdescribed in Section a), in the presence of unique anti-discolorationadditive packages consists of a UV absorber selected from Class A, aphenolic antioxidant from Class B, a secondary amine antioxidant fromClass C and a lactone antioxidant from Class D. The inventive liquidpolymeric lactone antioxidants are used in this unique additive packageto replace the commercial antioxidant Irgnox® HP-136 which is solidand/or may not thoroughly miscible with polyols. The foams are made withthe inventive additive packages, as well as commercially availableadditive packages, the foam buns are then sliced in half and 2 sets ofsmall pieces of foam samples (diameters of 10 cm×5 cm×2 cm) were cutfrom the center of each foam bun. One set of these foam samples weretested under Xenon lamp and compared the performance against UVdiscoloration (Xenon lamp test according to AATCC Test No. 16-1999) andAnother set of samples were tested under NOx gas chamber (NOxconcentration is 1 ppm) for discoloration at different exposure time(gas fading test as described in MTCC Test No. 23-1999). Those foamsamples exposed to different amounts of time under UV lamp or in the NOxchamber were then compared reading in CMC for delta E with respectedunexposed foam samples. The inventive synergistic additive compositionpackages are listed in Table 6. Also included in Table 6 ascomparatives, are control (with no additive) and commercially availableadditive packages B-75 (Ciba), CS-31 (Crompton) and LS-1 (Ortegol),which are current best commercial products in polyurethane industry forstabilization of white polyurethane foams. TABLE 6 Additive Compositionsand Loadings in Foam Formulation Additive Class A Class B Class CLactone AO package (php) (php) (php) (php) AA Tinuvin 326 Irgnox 1135Irgnox 5057 HP-136 (1.5) (0.33) (0.50) (0.57) BB Tinuvin 326 Irgnox 1135Irgnox 5057 Example 3 (1.5) (0.33) (0.50) (1.18) CC Tinuvin 326 Irgnox1135 Irgnox 5057 Example 4 (1.5) (0.33) (0.50) (0.57) DD Tinuvin 326Irgnox 1135 Irgnox 5057 Example 4 (1.5) (0.33) (0.50) (1.16) GG TinuvinB75 (commercially available from Ciba), loading @ 3.0 php HH CS-31(commercially available from Crompton), loading @ 3.0 php JJ LS-1(commercially available from Goldschmidt), loading @ 3.0 php Control 0  0   0   0  

Lighffastness and gas fade test results for the inventive andcomparative sample foams are summarized in Table 7. TABLE 7 Test Resultsfor Inventive and Comparative Additive Packages Lightfastness Gas FadeGas Fade Sample Additive delta E delta E delta E Foam # Package (13 hrs)(2 hrs) (4 hrs) A25 Control (N/A) 34.6 34.2 56.2 A26 AA 8.7 8.8 21.2 A27BB 7.7 10.8 27.6 A28 CC 11.6 11.8 33.4 A29 DD 10.0 11.3 23.5 A30 GG 15.834.1 82.5 A31 HH 18.2 51.4 53.1 A32 JJ 13.5 37.3 53.6

Clearly, the inventive additive packages containing the inventive liquidpolymeric lactone antioxidants exhibited among the best overallperformance against discoloration of UV exposure and gas fade, comparingto state-of-the-art commercial additive packages such as GG, HH and JJ.

It is understood by one of ordinary skill in the art that the presentdiscussion is a description of exemplary embodiments only, and is notintended as limiting the broader aspects of the present invention. Theinvention is shown by example in the appended claims.

1. A compound having the structural formula:

wherein: R₁-R₈ are independently selected from the group consisting of:H, F, Cl, Br, I, C₁-C₂₀ alkyls, C₁-C₂₀ cycloalkyls, C₁-C₂₀ alkoxygroups, C₇-C₂₀ phenylalkyls, and phenyl groups; A comprises a C₂-C₂₀alkyl group or a divalent oligomeric oxyalkylene radical; Z comprises aC₂-C₂₀ alkyl or a divalent oligomeric ester radical; and G comprises anend group selected from the group consisting of: H, C₁-C₁₀ alkyls, alkylcarbonyls and aryl carbonyls.
 2. The compound of claim 1 wherein said Acomprises a divalent oligomeric oxyalkylene radical having thestructure:

wherein: EO comprises ethylene oxide or a derivative thereof; POcomprises propylene oxide or a derivative thereof; R₉ comprises adivalent C₁-C₂₀ alkyl radical; x, y and w are independently selectedfrom the group consisting of: zero and positive integers or fractionsbetween 1 and 20; the sum of x+y+w is equal to or greater than 1; andR₁₀ comprises either H or a C₁-C₂₀ alkyl group.
 3. The compound of claim1 wherein Z comprises a divalent oligomeric ester radical, said radicalhaving the structure:

wherein: R₁₁ and R₁₂ are independently selected from H or C₁-C₁₀ alkylgroups; n comprises an integer between 1 and 10; and m comprises anypositive integer or fraction between 1 and
 20. 4. The compound of claim2 wherein Z comprises a divalent oligomeric ester radical, said radicalhaving the structure:

wherein: R₁₁ and R₁₂ are independently selected from H or C₁-C₁₀ alkylgroups; n comprises an integer between 1 and 10; and m comprises anypositive integer or fraction between 1 and
 20. 5. A compound representedby the formula:

wherein: R₁ and R₃ are independently selected from the group consistingof: H, F, Cl, Br, I, C₁-C₂₀ alkyls, C₁-C₂₀ cycloalkyls, C₁-C₂₀ alkoxygroups, C₇-C₂₀ phenylalkyls, and phenyl groups; and q is a positiveinteger between 1 and 20, and t is a positive integer between 0 and 20,and wherein the sum of q+t is equal to or greater than
 3. 6. A compoundrepresented by the formula:

wherein: q is a positive integer between 1 and 20, t is a positiveinteger between 0 and 20, and wherein the sum of q+t is equal to orgreater than
 3. 7. A compound represented by the structural formula:


8. A compound represented by the structural formula:


9. A composition comprising: a) an organic material which is subject tooxidative, thermal or light-induced degradation, and b) at least onecompound of formula:

wherein: R₁-R₈ are independently selected from the group consisting of:H, F, Cl, Br, I, C₁-C₂₀ alkyls, C₁-C₂₀ cycloalkyls, C₁-C₂₀ alkoxygroups, C₇-C₂₀ phenylalkyls, and phenyl groups; A comprises a C₂-C₂₀alkyl group or a divalent oligomeric oxyalkylene radical; Z comprises aC₂-C₂₀ alkyl or a divalent oligomeric ester radical; and G comprises anend group selected from the group consisting of: H, C₁-C₁₀ alkyls, alkylcarbonyls and aryl carbonyls.
 10. The composition of claim 9 wherein Acomprises a divalent oligomeric oxyalkylene radical having thestructure:

wherein: EO comprises ethylene oxide or a derivative thereof; POcomprises propylene oxide or a derivative thereof; R₉ comprises adivalent C₁-C₂₀ alkyl radical; x, y and w are independently selectedfrom the group consisting of: zero and positive integers or fractionsbetween 1 and 20; the sum of x+y+w is equal or greater than 1; and R₁₀comprises H or a C₁-C₂₀ alkyl group.
 11. The composition of claim 9wherein Z comprises a divalent oligomeric ester radical, said radicalhaving the structure:

wherein: R₁₁ and R₁₂ are independently selected from the groupconsisting of: H and C₁-C₁₀ alkyl groups; n comprises an integer between1 and 10; and m comprises any positive integer or fraction between 1 and20.
 12. The composition of claim 9 wherein said organic materialcomprises a synthetic polymer.